1. Field of the Invention
This invention relates to a temperature stabilization circuit and more particularly to such a circuit used for stabilizing an inverting gate ring oscillator.
2. Description of the Prior Art
Time base oscillators are needed in integrated circuit test systems to measure time intervals starting precisely from irregularly occurring external events. The most common prior art test system oscillators are phase locked. The frequency deviations that inevitably occur when a phase locked oscillator is unlocked for synchronous restarting introduce unsatisfactory errors. Stop-restart inverting gate ring oscillators have not often been used in test systems to provide time base signals because of such oscillator's high temperature dependence. To be sufficiently accurate, stop-restart oscillators need to operate at a stabilized temperature. Attempts have been made to temperature stabilize them in several ways, including heating the oscillator in a "constant" temperature oven, but prior art techniques have not provided sufficiently accurate control over the temperature and frequency.